It is known, e.g. from German patent document No. 29 20 707 and the corresponding U.S. Pat. No. 4,408,727, for example, to provide a process for automatically introducing a web-coiling core in the pocket defined by the support rolls of a double-roll-coiling machine in which the web, e.g. a paper web, is severed and the resulting free end of the paper web, after removal of the completed coil, is affixed to the web-coiling core. The latter is previously provided with an adhesive enabling the free end of the web to adhere to the core so that, when the core is positioned in the pocket so as to be cradled in the downwardly converging crevice between the rolls, also referred to as the wedge, rotation of the rolls can cause the web to wind upon the core and form another coil.
In the apparatus, moreover, the core is initially transferred from a waiting position, which is defined by the apparatus, into a transfer position in which the core is located above the pocket and is then transferred from the latter position onto the support rolls into the coiling or winding position.
The afore-described process and apparatus makes use of a holder for the core which comprises a pair of tongues or jaws which grip the core in the transfer position above the roll bed and carry the core into the pocket of bed. The core, of course, should be held in an exactly defined position so that the trace of adhesive or glue thereon can properly encounter the free end of the web which is to be applied thereto. Usually the glue trace or strip is downwardly oriented.
However, in practice, the gripper which has retained the core in its transfer position opens to allow the core to pass by free fall into the pocket and onto the rollers. In most cases, the glue trace or adhesive strip, if properly oriented on the undersides of the core, will simply enter the crevice formed by the roll bed without problems. The glue trace or adhesive strip does not come into contact with the support rolls and directly adheres the free end of the web to the core. However, this is not always the case in practice, when one utilizes web-coiling cores of large outer diameter, the grippers for the cores must be located substantially higher above the bed and thus the core must pass through a greater free fall before being caught by the rolls.
Naturally, if the grippers are positioned at such higher levels to accomodate larger diameter cores, then when the apparatus is used for smaller diameter cores, the free fall distance is even greater.
Especially in the latter case, i.e. when small cores are used in an apparatus capable of handling large cores, the free fall, in particular upon the rolls and even the free fall itself induces a rotation in the core which can cause the adhesive or glue on the core to contact one or the other roll and contaminate it. Contamination is also possible in this manner of any pressure roll which may be provided to apply pressure to the core.